|This needs a stretch.|
The mansion belonged to Dr. Jekyll.
- Helga (maid)
Scooby-Doo, Where Are You!
Insert details here.
- Although not explicit, the mansion could be retconned into being situated in Coolsville, the home town of the gang during their pre-adolescence, as established in A Pup Named Scooby-Doo.
- It's unknown what happened to the mansion (or Helga's job) when Dr. Jekyll was taken into custody.